Don't check in is the key
This ^^^^. Don't check in the key. Get a seat assignment beforehand as suggested above. Check in only if you plan to fly.
It's a pain to manually off load you from a flight if you checked in. I did it but was at T-23 using BA avios on AA metal and then found a better flight directly on AA. The off loading took a while and fortunately the VA agent worked it out directly with an AA agent without me